title: Assessing the role of the RND efflux pump in metronidazole resistance of Helicobacter pylori by RT-PCR assay.
abstract: BACKGROUND
  Metronidazole is a significant antibiotic used for eradication of Helicobacter pylori infections and it is of notice that metronidazole-resistant clinical isolates have been found in high rates worldwide. While the RND family of efflux pumps plays a central role in drug resistance among Gram-negative bacteria, this is questionable for H. pylori.
  
  
  METHODS
  To understand whether TolC homologues of RND pumps contribute to metronidazole resistance in H. pylori isolates, expression of four TolC homologous genes of five resistant clinical isolates exposed to varying concentrations of metronidazole were evaluated by RT-PCR and transcriptional analysis.
  
  
  RESULTS
  The results indicate that excess amounts of metronidazole are able to increase the expression level of these genes at the transcriptional stage.
  
  
  CONCLUSIONS
  Therefore, it may be hypothesized that use of metronidazole in H. pyori infection can induce metronidazole resistance. Furthermore, the RND family of efflux pumps may contribute to metronidazole resistance in clinical isolates of H. pylori.
authors.affiliation: MARS bioinformatics Institute, Tehran, Iran.
authors.forename: Jalil Fallah
authors.initials: JF
authors.lastname: Mehrabadi
authors.forename: Mehrandokht
authors.initials: M
authors.lastname: Sirous
authors.forename: Naser Ebrahimi
authors.initials: NE
authors.lastname: Daryani
authors.forename: Saeed
authors.initials: S
authors.lastname: Eshraghi
authors.forename: Bahram
authors.initials: B
authors.lastname: Akbari
authors.forename: Mohammad Hasan
authors.initials: MH
authors.lastname: Shirazi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008795:Metronidazole / Q000378:metabolism / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D026901:Membrane Transport Proteins; D008795:Metronidazole